Electric vehicle charging device and method using VIB ESS

Abstract

Embodiments of the present invention receive power from at least one of a power grid and an energy storage device (ESS), execute an electric vehicle charging procedure through a charger, receive power from at least one of the power grid and the energy storage device (ESS), and execute the charging procedure through the charger, and during the electric vehicle charging procedure, it is possible to charge the energy storage device (ESS) from the power grid or switch from discharging of the energy storage device (ESS) to charging, and an electric vehicle charging method is presented which is characterized by this.

Description

Technical Field

[0001] The present invention relates to an integrated system combining an energy storage device (ESS) and a charger, and more particularly to a system configuration and control method for electric vehicle (EV) charging that reflects the overall energy or power supply situation of the integrated system.

Background Art

[0002] An energy storage device (Energy Storage System, ESS) is a device that stores electricity in a battery or the like and then supplies power to the grid. The energy storage device can perform charging and discharging.

[0003] In recent years, as the use of electric vehicles has expanded, electric vehicle chargers have been placed in various spaces. However, the use of electric vehicle chargers increases the electricity consumption of the grid and may affect other electricity consumption in the corresponding space. In particular, when the electricity consumption suddenly increases, there is a problem that the use of electric vehicle chargers is restricted.

[0004] In response, there is a need for a measure to provide a system for stably charging in the space where the charger is placed.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide an electric vehicle charging system that stabilizes the power supply of the grid by the energy storage device assisting the power use of the charger and drives in cooperation with the ESS power.

[0006] Another problem to be solved by the present invention is to provide a charging system in which charging / discharging of the ESS is performed simultaneously during charging of an electric vehicle. An additional problem to be solved by the present invention is to provide a system in which the difference between the SoC of the ESS at the start of charging of the electric vehicle and the SoC of the ESS after the charging of the electric vehicle is below a certain level.

[0007] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned here will be clearly understood by those skilled in the art from the following description.

Means for Solving the Problems

[0008] According to an embodiment of the present invention, there is provided an electric vehicle charging method, which receives power from at least one of a power grid and an energy storage device (ESS), executes an electric vehicle charging procedure through a charger, receives power from at least one of the power grid and the energy storage device (ESS), and executes the charging procedure through the charger, and during the electric vehicle charging procedure, it is possible to charge the energy storage device (ESS) from the power grid or switch the energy storage device (ESS) from discharging to charging.

[0009] According to an embodiment of the present invention, in an electric vehicle charging system in which a power grid connected to an energy storage device (ESS) has a maximum power amount and a charger connected to the energy storage device (ESS) and the power grid has a required power amount required for charging an electric vehicle, when the required power amount is greater than or equal to the maximum power amount, a first step of discharging the energy storage device (ESS) for the power in the range exceeding the maximum power amount to charge the electric vehicle; and when the required power amount is less than the maximum power amount, a second step of charging the energy storage device (ESS) with power in the range below the maximum power amount.

[0010] According to an embodiment of the present invention, there is provided at least one secondary battery capable of charging and discharging; an input unit for providing power from a power grid to charge the secondary battery; an output unit for discharging the secondary battery and providing the corresponding power to a charger for charging an electric vehicle; and a control unit operatively connected to the secondary battery, the input unit, and the output unit, and configured to control so as to maintain the state of charge (SoC) of the secondary battery at the start of charging of the electric vehicle and the state of charge (SoC) of the secondary battery at the end of charging of the electric vehicle to be similar. The charging procedure is executed through the charger by receiving power from at least one of the power grid and the energy storage device (ESS), and it is possible to switch from charging or discharging of the energy storage device (ESS) from the power grid to charging during the electric vehicle charging procedure. An electric vehicle charging system is provided.

[0011] According to an embodiment of the present invention, in an electric vehicle charging system in which a power grid connected to an energy storage device (ESS) has a maximum power amount and a charger connected to the energy storage device (ESS) and the power grid has a required power amount required for electric vehicle charging, when the required power amount is less than the maximum power amount, a second stage of charging the energy storage device (ESS) with power in a range below the maximum power amount is included. The charging procedure is executed through the charger by receiving power from at least one of the power grid and the energy storage device (ESS), and it is possible to switch from charging or discharging of the energy storage device (ESS) from the power grid to charging during the electric vehicle charging procedure. An electric vehicle charging method is provided.

Advantages of the Invention

[0012] When implementing an embodiment of the present invention, the energy storage device can assist in the power use of the charger to stabilize the power supply of the grid, whereby the charger can provide a stable electric vehicle charging service.

[0013] When implementing the embodiments of the present invention, it is possible to provide a charging system in which charging / discharging of the ESS is performed simultaneously during the charging of an electric vehicle. When implementing the embodiments of the present invention, it is possible to provide a system in which the difference between the SoC of the ESS at the start of charging of the electric vehicle and the SoC of the ESS after the end of charging of the electric vehicle is within a certain range.

[0014] The effects provided by the present invention are not limited to the effects mentioned above, and other effects not mentioned here will be clearly understood by those skilled in the art from the following description.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0016] The advantages and features of the invention presented in this specification, and the methods for achieving them, will become clear by referring to the embodiments described in detail hereinafter together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed in this specification and can be realized in various different forms. Merely, these embodiments are provided to make the disclosure of the present invention complete and to fully inform those with ordinary knowledge in the technical field to which the present invention pertains of the scope of the invention. The present invention is defined only by the scope of the claims. The same reference numerals may refer to the same components throughout this specification.

[0017] Also, in the description of the present invention, when it is determined that a specific description of related known configurations or functions may obscure the gist of the present invention, the detailed description thereof may be omitted.

[0018] Also, when describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are merely for distinguishing the components from other components, and do not limit the essence, order, sequence, or number of the corresponding components. When a component is described as being "connected", "coupled", or "joined" to another component, it should be understood that the component may be directly connected to the other component or can be connected, but there may be other components "intervening" between the components, or the components may be "connected", "coupled", or "joined" through other components.

[0019] Hereinafter, this specification will describe a technique in which an energy storage device installed in a space such as a building, a house, a subway, or a public place controls the charging and discharging of the energy storage device according to the electrical usage status of other electrical devices in the space. Also, a technique in which the energy storage device controls a charger according to the aforementioned electrical usage status will be described. And, when the power usage load of other electrical devices in the space increases, a technique in which the energy storage device supplies power to the other electrical devices will be described.

[0020] Generally, an energy storage system (ESS) consists of a battery, a battery management system (BMS), a power conversion system (PCS), an energy management system (EMS), etc. The battery has one or more cells, multiple cells form one module, and multiple modules can form one rack. The energy storage system (ESS) configured in this way can be connected to a power grid, an electrical network, a power grid, etc. to supply power.

[0021] The energy storage system (ESS) can be used for charging an electric vehicle (EV). Here, the battery applied to the energy storage system (ESS) and the battery applied inside the electric vehicle (EV) each have a state of charge (SoC), and the background explanation is as follows.

[0022] First, it is necessary to understand the charge / discharge rate (C-Rate) of the battery. The charging rate and / or the discharging rate of the battery can be controlled by the charge / discharge rate (C-Rate). The charge / discharge rate (C-Rate) means the measurement of the current used for charging and / or discharging the battery. As an example, the meaning that a specific battery discharges at 1C-Rate or 1C means that a battery with a capacity of 10Ah (that is, the amount of electricity when a current of 10A (ampere) flows for 1 hour) can discharge 10A (ampere) in 1 hour from a fully charged state. In this way, the charging rate of the battery can also be expressed in C-Rate.

[0023] When measuring a battery charged at a specific C-Rate, the corresponding state of charge (SoC) can be confirmed. When charging an electric vehicle (EV) using the energy storage system (ESS), various controls related to charging can be performed by checking the SoC of the battery inside the energy storage system (ESS), the SoC of the battery inside the electric vehicle (EV), etc.

[0024] The embodiments of the present invention described below relate to system control required when charging an electric vehicle (EV) using an integrated system in which an EV charger is applied to an energy storage device (ESS). The present inventors present features that are technically improved compared to conventional or existing ESS system configurations and controls. The features of the present invention can also be expressed as an EV charging system that operates in cooperation with ESS power.

[0025] Hereinafter, the features of the present invention will be described in more detail with reference to embodiments. FIG. 1(a) is a diagram showing the power supply configuration of the power grid 110, the energy storage device 140, and other electrical devices 120, 130, 150, 160, 170 in the power supply system 100 related to an embodiment of the present invention.

[0026] Generally, the power supply system 100 has a main distribution board 120 that is supplied with power, that is, alternating current (AC), from the power grid 110, and the corresponding power is distributed and provided to a power conversion system (PCS), a power bank, or a similar power conversion device 130. On the other hand, the main distribution board 120 is also connected to the ESS external load 170 and can supply power.

[0027] The power conversion device 130 is operatively connected to an energy storage device 140 such as a VIB ESS and can provide necessary control to transmit and receive power. The power conversion device 130 is also connected to a charger 150, and the charger 150 can be connected to an electric vehicle (EV) 160 or other object that needs to be charged. The electric vehicle (EV) 160 can be selectively supplied with at least one of the power provided from the power grid 110 and the power provided from the energy storage device 140 under the control of the power conversion device 130.

[0028] Here, at least one of the main distribution board 120, the power conversion device 130, the energy storage device 140, the charger 150, the electric vehicle (EV) 160, and the ESS external load 170 can be installed at a designated location, for example, inside or adjacent to a specific building.

[0029] It is desirable to install and control such a power supply system 100 to supply grid power to a specific building and also perform electric vehicle charging together. Therefore, the output for the parts indicated by A, B, and C in Fig. 1(a) will be described more specifically in Fig. 1(b).

[0030] Fig. 1(b) is a conceptual diagram for explaining the output for the parts indicated by A, B, and C in the aforementioned Fig. 1(a). Figs. 1(a) and (b) have a configuration combining an ESS and a charger, and correspond to a technique of performing ESS charging after charging is completed while assisting with the ESS so as not to exceed the contract power of the grid.

[0031] The graph of output A represents the charger output over time, and the charging of the electric vehicle is performed while being supplied with power from the grid and the ESS. It can be seen that the maximum output appears at the start and initial stage of electric vehicle charging, the output of the charger decreases as time passes, and reaches the lowest level as the end of electric vehicle charging approaches. The contract power related to the grid is shown at an exemplary constant level and will be described in more detail below.

[0032] The graph of output B represents the grid output over time, and it can be seen that the maximum output appears at the start and initial stage of electric vehicle charging, the output of the charger decreases as time passes, and reaches the lowest level as the end of electric vehicle charging approaches.

[0033] The graph of output C represents the ESS output according to the passage of time. It can be seen that at the start and initial stage of electric vehicle charging, the maximum output appears. As time passes, the output of the charger decreases and reaches the lowest level when the electric vehicle charging is approaching completion. Here, the maximum output of the ESS is the value obtained by subtracting the contract power of the grid mentioned above from the maximum output of the charger.

[0034] Figure 1(c) is a conceptual configuration diagram related to an embodiment of the present invention. Power is provided from the power grid for electric vehicle charging and supplied to the electric vehicle charger after the corresponding AC / DC conversion. The energy storage device (ESS) includes a switching circuit in the corresponding AC / DC conversion unit when charging and discharging while assisting the power of such a grid, and it is possible to execute the switching between discharging and charging of the energy storage device during the electric vehicle charging procedure.

[0035] Therefore, it can be said that the embodiment of the present invention provides an electric vehicle charging method characterized in that it receives power from at least one of the power grid and the energy storage device and executes a charging procedure through a charger, and it is possible to execute the switching between discharging and charging of the energy storage device according to the state of the power grid during the electric vehicle charging procedure.

[0036] Next, the relationship between the output of the charger, the output of the ESS, and the state of charge (SoC) will be described more specifically. Figure 2(a) is a conceptual diagram related to the relationship between the output of the charger, the output of the ESS, and the state of charge (SoC) according to the first embodiment of the present invention.

[0037] Following the description of FIGS. 1(a) and 1(b) above, when starting to charge the first EV (electric vehicle), an output of the charger exceeding the contract power of the grid is required, and a case is shown where the electric vehicle is first charged with the ESS output. As time passes, the output of the charger decreases due to continuous discharge of the ESS, and in the section below the grid contract power, charging is continued with the grid power until the end of charging of the first EV. After that, when attempting to immediately charge the second EV, it cannot be immediately used by discharging the ESS. That is, as can be seen by measuring the SoC of the ESS, the SoC reaches almost 0% at the end of charging of the first EV.

[0038] When EV charging starts with the ESS fully charged, the ESS can assist and charge at the maximum output. If the capacity of the ESS is approximately the same as the amount of power to assist the EV, after charging one EV, it may be difficult to assist the second EV. To solve this, the capacity of the ESS can be increased, but there is a problem that the overall cost increases and the profitability decreases. As another method, the ESS can be recharged, but there is a problem that the number of charging EVs decreases due to the standby time during recharging and the profitability decreases.

[0039] On the other hand, it can be seen that there is an area where the contract power of the grid is wasted during the latter half of the charging of the first EV. Therefore, the inventors of the present invention recognized the problem regarding such a wasted area and decided to conduct research and development on a technical method that can be improved.

[0040] FIG. 2(b) is a conceptual diagram regarding the relationship between the output of the charger, the output of the ESS, and the charge state (SoC) according to an additional embodiment of the present invention. To explain the background, lithium-ion batteries (LIBs) currently used for electric vehicle charging can be fast-charged at low state of charge (SoC) due to their electrochemical characteristics. However, when the SoC exceeds a certain level, charging speed is reduced for safety reasons. Even when an ultra-fast charger is applied, ultra-fast charging only proceeds in the initial stage, and after a certain point, the charging mode switches to slow charging, which is insufficient for the EV charging process. In other words, the energy storage system (ESS) that assists the power grid needs to supply optimal power according to the power demand of electric vehicles. It can be seen that a vanadium redox flow battery (VIB) with a wide charge / discharge rate (C-rate) coverage (coverage: available range) is an optimized battery for the ESS.

[0041] Therefore, the inventors have developed a charging system in which charging / discharging of the ESS is performed simultaneously during electric vehicle charging. That is, in the high-speed charging section of the electric vehicle, the ESS discharges to assist the power of the power grid, and then, when entering the low-speed charging section of the electric vehicle, charging of the ESS occurs according to the state of the power grid. As a result, it can be said that the system has a difference in the SoC of the ESS at the start of electric vehicle charging and the SoC of the ESS after the end of electric vehicle charging that is below a certain level.

[0042] In addition, the inventors have found that a VIB ESS that can handle changes in charging / discharging output from low to high power is suitable because the change in charging / discharging output is large depending on the state of the power grid. The inventors propose to use it for VIB ESS charging in the region where the contract power of the grid shown in Fig. 2(a) above is wasted.

[0043] Here, charging may be performed on at least one battery, at least one cell, at least one module, and / or at least one rack in the VIB ESS.

[0044] First, when electric vehicle charging occurs continuously, if the charger output drops below a specific reference value, for example, the contract power (of the power grid), the excess output can be used for ESS charging. By performing the necessary control here, it is characterized in that the SoC of the ESS does not change until the first EV charging is completed and before the charging of the next second EV occurs. That is, in order for EV users to be able to use the charger in the best state at all times, the inventors have devised a charging system in which both ESS charging and discharging are performed during the electric vehicle charging process so that grid power can be supplied to a specific building while additionally performing electric vehicle charging together.

[0045] At this time, since a full charge and discharge cycle occurs for each EV in the ESS, a long-life VIB is advantageous. In some cases, the charger operator may be able to maintain the maximum charging speed even when using an ESS with a capacity of about half that of one EV.

[0046] Figure 2(c) is a conceptual diagram regarding another relationship between the output of the charger, the output of the ESS, and the state of charge (SoC) according to an additional embodiment of the present invention. When electric vehicle charging is interrupted midway, some EV users may interrupt and operate the charging when the electric vehicle charging speed drops below a certain level. Therefore, it may be necessary to secure a part of the ESS charging time or to lower the maximum output to a certain level while securing the ESS charging time.

[0047] This is shown as a region of a short waiting time in Figure 2(c), showing the relationship between the corresponding charger output, ESS output, and ESS SoC. If the electric vehicle charging ends before reaching the switching reference value from ESS discharge to charging, after securing the ESS charging time for a certain period, control is performed to resume ultra-fast charging.

[0048] Alternatively, when the charging of the electric vehicle is completed before the switching reference value from ESS discharge to charging is reached and the ultra-fast charging immediately proceeds, control is performed to down-regulate the ultra-fast charging power of the electric vehicle. For example, such control can also be executed when the ESS is difficult to discharge.

[0049] Next, with reference to FIGS. 3(a), 3(b), 4(a), and 4(b), the output of the charger according to an additional embodiment of the present invention will be described in more detail. FIG. 3(a) is a graph showing the output of the ultra-fast charging mode 1 for the charger 360 of the power supply system 300 according to an additional embodiment of the present invention.

[0050] The ultra-fast charging mode 1 is executed when there is no need to supply power to loads other than the ESS. As a first step, the maximum amount of power available in the grid where the ESS is installed is confirmed. The second step is to receive charger required power amount information. In the third step, a comparison and determination are made regarding the power amounts in the first and second steps.

[0051] Here, for the confirmation and comparison determination of various power amounts, monitoring or monitoring means, devices, sensors, measuring instruments, meters, power meters, etc. can be utilized, and for the transmission and reception of the corresponding power amount information, wired communication or wireless communication devices and technologies such as Wi-Fi can be utilized.

[0052] Finally, when the charger required power amount is greater than or equal to the grid power amount, the range exceeding the grid power amount is assisted by the ESS, or when the charger required power amount is less than the grid power amount, the range below the grid power amount is used for ESS charging.

[0053] On the other hand, the output range of the charger where the output is greater than or equal to the contract power of the power grid is called phase 1, and the output range where the output is less than the contract power of the power grid can be called phase 2. FIG. 3(b) is a conceptual diagram showing the power supply in phases 1 and 2 of FIG. 3(a). Here, the part indicated by the dotted arrow shows the power supply direction.

[0054] For the charging of the electric vehicle (EV) 360, the main distribution board 320 sends the power provided by the power grid 310 to the power conversion device (330: PCS, Power Bank). In Phase 1, which is the interval where the contract power of the power grid is exceeded, the VIB ESS discharges and charges the EV through the power conversion device 330 and the charger 350. On the other hand, in Phase 2, which is the interval where the contract power of the power grid is not reached, the surplus power of the power grid is not wasted and is used for charging the VIB ESS, and the power of the grid charges the EV through the power conversion device 330 and the charger 350.

[0055] Figure 4(a) is a graph showing the output of the ultra-fast charging mode 2 for the charger 360 of the power supply system 300 according to an additional embodiment of the present invention. The ultra-fast charging mode 2 is executed when it is necessary to provide power to loads other than the ESS. As the first step, the maximum amount of power available in the grid where the ESS is installed is confirmed. In the second step, the charger required power amount information is received. The third step is to receive the required power amount information of the loads outside the ESS. In the fourth step, the power amounts in the first, second, and third steps are compared and judged.

[0056] Here, for the confirmation and comparison judgment of various power amounts, monitoring or monitoring means, devices, sensors, measuring instruments, power meters, etc. can be used, and for the transmission and reception of the corresponding power amount information, wired communication or wireless communication devices and technologies such as Wi-Fi can be utilized.

[0057] Finally, when the sum of the charger required power amount and the loads outside the ESS is greater than or equal to the grid power amount, the range exceeding the grid power amount is assisted by the ESS, or when the sum of the charger required power amount and the loads outside the ESS is less than the grid power amount, the range below the grid power amount is used for charging the ESS.

[0058] On one hand, the section where the output of the charger provides power to the grid contract power or above / exceeding section and the off-ESS load can be called Phase 1, and the power section below / less than that can be called Phase 2. Here, due to the off-ESS load, it can be seen that Phase 1 in Fig. 4(a) is longer than Phase 1 in Fig. 3(a), and Phase 2 in Fig. 4(a) is shorter than Phase 2 in Fig. 3(a).

[0059] Fig. 4(b) is a conceptual diagram showing the power supply in Phase 1 and Phase 2 of Fig. 4(a). Here, the part indicated by the dotted arrow shows the power supply direction. To supply power to the off-ESS load 370, the main distribution board 320 provides a part of the power from the power grid 310. Additionally, for charging the electric vehicle (EV) 360, the main distribution board 320 sends the power provided from the power grid 310 to the power conversion device (330: PCS, Power Bank). In Phase 1, which is the section exceeding the grid contract power, the VIB ESS discharges to charge the EV through the power conversion device 330 and the charger 350. On the other hand, in Phase 2, which is the section less than the grid contract power, the surplus power of the power grid is not wasted and is used for charging the VIB ESS, and the power of the grid charges the EV through the power conversion device 330 and the charger 350.

[0060] For reference, Figs. 4(a) and 4(b) exemplarily show the case where the power supply system 300 is installed and operated in places such as commercial facilities, public places, and specific buildings.

[0061] FIG. 5 is a diagram showing a configuration in which an energy storage device is arranged in a space according to an embodiment of the present invention and a configuration of power supply to other electrical devices. FIG. 1 shows an energy storage system (ESS) 100 and other devices, and the grid corresponding to the power source 10 can supply power to a supportive power region 30 and a primary power region 40. The energy storage device (ESS) 100 can be arranged in the supportive power region 30.

[0062] The energy storage device (ESS, 100) and one or more chargers 50a,..., 50n can be arranged in the supportive power region 30. A number of electrical devices 60a,..., 60n can be arranged in the primary power region 40. Also, another ESS different from the energy storage device 100 arranged in the supportive power region 30 can be arranged in the primary power region 40.

[0063] In the embodiment of FIG. 5, the power distribution device 20 can distribute power to the supportive power region 30 and the primary power region 40. The energy storage device 100 can be charged or discharged according to the electrical demand or predicted demand used in the two regions 30 and 40. For this purpose, a power measuring device 210 can be arranged connected to or inside the supportive power region 30. Also, a power measuring device 220 can be arranged connected to or inside the primary power region 40.

[0064] The power measuring devices 210, 220 are an example of a power quantity measuring device (power meter) and measure the power quantity being used in the installed region. The power measuring devices 210, 220 transmit the measured value (power quantity) to the energy storage device 100. Also, according to an embodiment of the present invention, another power measuring device can be arranged in the power source 10. In this case, the energy storage device 100 can confirm the magnitude of the power consumption of the power source 10 in real time.

[0065] In this specification, the energy storage device includes an energy storage device including a vanadium ion battery, but the present invention is not limited thereto. For example, in this specification, the energy storage device includes a VRB (Vanadium Redox Battery), a PSB (polysulfide bromide battery), a ZBB (zinc-bromine battery), and the like.

[0066] When applying the embodiment of FIG. 5, when the charger 50 charges an electric vehicle or another device that requires charging, charging can be performed according to the charging conditions required by the electric vehicle or another device. For example, when high-current charging is requested, the charger 50 performs high-current charging. According to the control of the energy storage device 100, the power of the power supply 10 and the energy storage device 100 is provided to the charger 50. When the charger 50 performs low-current charging, the energy storage device 100 can enable the charger 50 to be supplied with power from the power supply 10 for charging according to the power supply status of the power supply 10 or the power usage status of the primary power region 40.

[0067] FIG. 6 is a diagram showing a configuration in which a charger according to an embodiment of the present invention is supplied with power from an energy storage device 100 and a power distribution device 20. The charger 50 can be supplied with power from the power distribution device 20 (P1). In one embodiment, this is supplied with power from the grid, i.e., the power supply 10. And the energy storage device 100 can assist in part or all of the power used by the charger 50 by comparing the information on the amount of power received from the power measuring devices 211, 212, 220 with the maximum amount of power that can be provided by the corresponding power supply 10.

[0068] The energy storage device 100 can supply power to the charger 50 (P2). The charger 50 can switch or merge the supplied power according to the control of the energy storage device 100. The charger 50 can supply power according to the charging request of an external device (P5).

[0069] The energy storage device 100 can be supplied with power from the power distribution device 20 (P3). And the energy storage device 100 can supply power to the primary power region 40 (P4). The power supplied by the energy storage device 100 can be supplied to the primary power region 40 via the power distribution device 20. That is, the power supply direction between the energy storage device 100 and the power distribution device 20 can be bidirectional.

[0070] The power supply (P4) of the energy storage device 100 can be determined by the power demand of the primary power region 40, the maximum amount of power that the power source 10 can supply, etc. When the energy storage device 100 supports the fast charging and discharging functions of the charger 50, the energy storage device 100 can monitor the power amount of the grid 10 and flexibly respond to the power situation of the grid 10. In particular, the energy storage device 100 can accumulate and store information on the past power usage time of the grid 10 to predict the time period when the power usage amount of the grid 10 is low. As a result, the energy storage device 100 can be prepared for the case where the power usage of the grid 10 suddenly increases during the fast charging and discharging process of the charger 50.

[0071] Also, when fast charging of the energy storage device 100 is required, the above - mentioned process can also be applied. That is, the energy storage device 100 can be supplied with grid 10 power to carry out fast charging of the energy storage device 100. Even in this process, the power amount of the grid 10 as described above can be monitored to flexibly respond to the power situation of the grid 10.

[0072] FIG. 7 is a diagram showing the configuration of an ESS according to an embodiment of the present invention. The energy storage device 100 includes an energy storage module 110 including a battery and a controller 150.

[0073] The energy storage device 100 includes a pack BMS 120 that manages the charging and discharging of the energy storage module 110. Further, the energy storage device 100 can selectively include a PMS (Power Management System) 130 and a PCS (Power Conversion System) 140. When the energy storage device 100 includes all of the PMS 130 and the PCS 140, it can be called an integrated ESS.

[0074] The module BMS monitors the state of charge, state of discharge, temperature, voltage, current, etc. of the corresponding battery and manages the battery. The pack BMS 120 is a battery management system for the entire battery pack.

[0075] The controller 150 can use the power measurement results in the supportive power region and the power measurement results in the primary power region to determine the charging or discharging of the energy storage module 110, or to determine the availability of charging for one or more chargers arranged in the supportive power region or discharging to the primary power region. Further, according to one embodiment, the controller 150 can be integrated with the PMS 130 and operate as one component.

[0076] FIG. 8 is a diagram showing a process in which a controller controls an ESS according to the amount of power in a grid according to an embodiment of the present invention. The controller 150 can store the maximum amount of power (Grid_Max) of the grid, i.e., the power source 10, that supplies power to the primary power region and the supportive power region (S301). The maximum amount of power (Grid_Max) means the maximum amount of power that can be used in the grid.

[0077] Thereafter, the power meter 220 measures the power consumption (Primary_Usage) in the primary power region 40 (S302). In one embodiment, this measures the power consumption (load consumption) that occurs in a region other than the supportive power region 30 where the energy storage device 100 is arranged.

[0078] Also, according to another embodiment of the present invention, at step S302, the energy storage device 100 or the controller 150 can receive the total grid power consumption and the power usage in the primary power region.

[0079] Next, the controller 150 determines whether the charger 50 disposed in the supportive power region 30 is in use (S303). If there are multiple chargers 50, the controller 150 can determine whether each of them is in use. If the charger 50 is not in use, the controller 150 executes step S307. In step S307 where the controller 150 compares the amounts of power, if Grid_Max is greater than or equal to Primary_Usage when comparing Grid_Max and Primary_Usage, the controller 150 determines the ESS charge amount and proceeds with the charging (S311).

[0080] Then, the controller 150 measures the SOC (State of Charge) of the ESS (S312), and if it is equal to or higher than the SOC reference value, the charging ends. On the other hand, if the SOC of the energy storage device 100 is measured (S312) and is below the SOC reference value, the process after S302 can be repeated to control the charging of the ESS again.

[0081] On the other hand, if Grid_Max is less than Primary_Usage in S307, the controller 150 determines the discharge power amount of the energy storage device 100 and controls the energy storage device 100 to discharge to the primary power region 40 (S313). As a result, the excess grid power is assisted by the discharge of the energy storage device 100.

[0082] When the charger is in use in S303, the controller 150 measures the charging request power (Charging_Request) (S304). At this time, it is assumed that the SOC of the ESS is equal to or higher than the reference value. Then, the controller 150 compares the power (S305), but compares Charging_Request plus Primary_Usage (Charging_Request + Primary_Usage) with Grid_Max.

[0083] As a result of the comparison, if Grid_Max is less than (Primary_Usage + Charging_Request), the controller 150 determines the discharge power of the energy storage device 100 and controls the energy storage device 100 to discharge into the primary power region 40 (S313). As a result, the excess grid power is supplemented by the discharge of the energy storage device 100.

[0084] Also, as a result of the comparison in S305, if Grid_Max is greater than or equal to (Primary_Usage + Charging_Request), the controller 150 checks whether the difference (the excess grid power, see Equation 1 below) is greater than or equal to the grid margin reference value (S306).

[0085] [Equation 1] Excess grid power = Grid_Max - (Primary_Usage + Charging_Request) When the excess grid power is greater than or equal to the grid margin reference value, since the power is sufficient, the controller 150 determines the charging power of the energy storage device 100 and controls the energy storage device 100 to charge (S314). This means that the energy storage device 100 charges with a sufficient grid power margin.

[0086] On the one hand, when the surplus power of the grid is less than the grid surplus reference value, since it is highly likely that the grid power will not be able to meet the power demands of the supportive power region 30 and the primary power region 40 in the future, the controller 150 shifts the energy storage device 100 to the discharge standby mode (S315).

[0087] In the stages of charging the ESS in FIG. 8 (S311, S314), the controller 150 can execute the high current charging process of the battery. And continuously, the controller 150 receives the power measurement result of the primary power region. When the surplus power of the grid becomes low, the battery can be charged with low current or shifted to the discharge standby mode as in S315. Of course, even in the discharge standby mode, the controller 150 can monitor the overall grid power situation and the SOC of the battery and determine whether the battery can be charged with low power or high current.

[0088] FIG. 9 is a diagram showing the arrangement and operation of the ESS and the charger according to an embodiment of the present invention. FIG. 8 shows a configuration in which a vanadium ion battery (VIB ESS) 100a, which is an embodiment of the ESS, is arranged. The power supply process is in the order of the power source 10 which is the grid, the substation 5, the power meter 205, and the power distribution device 20a which takes the main distribution board as an example. Electricity is supplied from the power distribution device 20a to the VIB ESS 100a, the charger 50, and the ESS external load. The power meter 205 is arranged on the grid main power line, and the power meters 211, 212, and 220 can also be arranged separately for each line in the respective regions 30a and 40a. Information regarding the power consumption of each region and the whole is transmitted to the VIB ESS 100a.

[0089] As seen in FIG. 8 described above, VIB ESS100a stores information regarding the maximum amount of power (Grid_Max) that can be used in the grid. Also, VIB ESS100a can receive information regarding the amount of power supplied to the ESS external load (for example, the amount of power being used at 40a) from the power meter 220 arranged at 40a. Also, as an embodiment of the present invention, VIB ESS100a can receive the total power consumption of the grid (Grid_Usage) from the power meter 205.

[0090] The reception method can be either periodic reception or real-time reception. In the case of periodic reception, the corresponding period can be changed according to the change in the amount of power used in the primary power area 40a. For example, the controller 150 can set the reception period in units of 5 minutes at night when there is little change in the amount of power, and set the reception period in units of 1 minute during the day when there is a large change in the amount of power.

[0091] VIB ESS100a can control the charging or discharging of VIB ESS100a so that the power usage of the grid is optimized according to the amount of power used in the primary power area 40a. The drive modes of VIB ESS100a include a charging mode, a discharging mode, and a standby mode. In the charging mode, VIB ESS100a determines the ESS charge amount, proceeds with charging according to the SOC reference value of the ESS, and then ends the charging mode.

[0092] Also, VIB ESS100a can also assist all or part of the power output from the charger 50 (P11). For example, when the value obtained by subtracting the power usage amount in the primary power area 40a from the grid maximum power amount (available power amount) is smaller than the power amount output from the charger 50 (a shortage of the charger charging power amount occurs), VIB ESS100a can assist the shortage amount or an amount equal to or greater than the shortage amount. In the discharging mode, VIB ESS100a can receive the total power consumption of the grid from the power meter 205.

[0093] Also, when the Grid_Usage is equal to or greater than Grid_Max or the grid power runs out, VIB ESS100a can discharge the amount of power charged in the primary power area 40a. For example, when VIB ESS100a discharges to the power distribution device 20a like P10, the power distribution device 20a can supply this power to the primary power area 40a.

[0094] In addition, VIB ESS100a can also assist all or part of the power output from the charger 50 (P11). For example, when the value obtained by subtracting the total grid power consumption (Grid_Usage) from the maximum grid power (available power) is smaller than the power output from the charger 50 (indicating a shortage of charger charging power), VIB ESS100a can assist the shortage or more power than the shortage.

[0095] When applying the embodiment of FIG. 9, VIB ESS100a can optimize the grid power according to the in-grid power usage situation. For example, VIB ESS100a can assist the power to minimize the loss due to the over-power peak power and suppress the grid overload.

[0096] Therefore, after receiving the measurement result of the power amount in the primary power area, the controller 150 of VIB ESS100a can determine either the high-current charging or the low-current charging method for the battery. When the power amount in the primary power area is below a certain standard (e.g., 80% or less) compared to the total grid usage, VIB ESS100a can be quickly charged through high-current charging.

[0097] Conversely, when the power amount in the primary power area exceeds a certain standard (e.g., more than 80%) compared to the total grid usage, VIB ESS100a can be continuously charged through low-current charging to reduce the load on the entire grid and enable the future charged power to be used to assist the grid power.

[0098] FIG. 10 is a diagram showing the arrangement and operation of an ESS and a charger according to another embodiment of the present invention. Different from the configuration of FIG. 9, this is an embodiment in which a power distribution device 20a functioning as a main distribution board and a power distribution device 20b functioning as an ESS distribution board are separated. Furthermore, a power distribution device 20c functioning as a DC distribution board (container) for supplying power to the VIB ESS100b is separately arranged.

[0099] The power distribution device 20c can be configured by being divided into one or more, and the present invention is not limited to a specific configuration method of the power distribution device. The power distribution device 20c can be selectively arranged according to the configuration and arrangement of the VIB ESS100b, etc.

[0100] Although PMS130b and PCS140b are separately shown in FIG. 10, the present invention is not limited thereto, and PMS130b and PCS140b may be configured within the VIB ESS100b. The PMS130b can be integrated with the aforementioned controller 150 to control drive modes such as charging or discharging of the VIB ESS100b.

[0101] Also, the power bank 51 may be a component of the charger 50 according to the implementation mode of the invention, or may be a component independent of the charger 50. With the configuration of FIG. 9, the VIB ESS100a can assist the power of the entire grid. The VIB ESS100b stores information regarding the maximum power output of the power grid. And the VIB ESS100b can receive the total grid power consumption from the power meter 205. Or the VIB ESS100b can receive the measured value of the load usage outside the ESS to determine the available grid power. The VIB ESS100b can receive information regarding the total grid power consumption or receive the measured value of the load usage outside the ESS to control the charging or discharging of the VIB ESS100b.

[0102] The off-ESS load refers to the load for power consumption other than the VIB ESS100b and the charger 50, and means the load within the primary power area 40b such as power consumption in a building, at home, in a server, in a subway, etc.

[0103] Information about the maximum grid power can be input into the VIB ESS100b in advance. When the maximum grid power changes, the VIB ESS100b saves the changed value. The input value can be saved in the ESS100b and maintained for a certain period. The VIB ESS100b can save the maximum grid power (Grid_Max) information in a format such as 380V AC / 150KW.

[0104] When applying the embodiment of FIG. 10, a grid such as the power source 10 supplies power to the energy storage device 100b, the charger 50, and other loads (off-ESS loads) excluding the energy storage device and the charger. Also, the energy storage device 100b can include one or more power measuring devices 205, 211, 212, 220 that measure the power of the grid, the energy storage device 100b, the charger 50, and other loads (off-ESS loads).

[0105] Then, the controller of the energy storage device 100b can use any one or more of the grid power measured by the power measuring devices 205, 211, 212, 220 or the power of other loads to determine whether to charge or discharge the energy storage module, or to supply power to the charger or other loads.

[0106] In the case of an embodiment where the power of the grid can be confirmed by the power of other loads (off-ESS loads), the energy storage device 100b can use the value measured by the power measuring device 220 arranged on the off-ESS load to determine whether to charge or discharge the energy storage module, or to supply power to the charger or other loads.

[0107] On the other hand, when it is necessary to confirm the grid power amount with the power amount of other loads or to confirm the grid power amount in real time without error, the energy storage device 100b can determine the charging or discharging of the energy storage module using the value measured by the power measuring device 205 arranged in the power supply 10, or can determine to supply power to the charger or other loads.

[0108] FIG. 11 is a diagram showing a process in which the ESS operates in response to an increase in power usage in the grid according to an embodiment of the present invention. The controller 150 stores the maximum power amount available in the grid (Grid_Max) (S321). This can be provided by the aforementioned power supply 10 to the controller 150 with information regarding the maximum power amount. Alternatively, the maximum power amount of the power supply 10 can be input to the controller 150 in advance.

[0109] Thereafter, the power measuring device 220 measures the power usage amount (Primary_Usage) in the primary power region, and the controller 150 calculates the expected usage amount within N hours (S322). The controller 150 can cumulatively store the power usage amount (Primary_Usage) information in the primary power region. When the controller 150 monitors the power usage amount (Primary_Usage) in the primary power region in real time and the power usage amount increases, it calculates the expected usage amount within N hours.

[0110] At this time, the controller 150 can calculate the expected usage amount reflecting seasonal factors. As an example, the controller 150 can calculate the expected usage amount based on information regarding a time period when there is a high possibility of using an air conditioner in the corresponding space (building, house, etc.) (for example, 2 pm to 4 pm).

[0111] As a result, the controller 150 can determine whether the power consumption (Primary_Usage) of the current primary power region belongs to a stable range or is below the reference value, but whether the predicted power consumption within N hours deviates from the stable range or exceeds the reference value (S323). In this case, the controller 150 proceeds to a standby mode in which it can assist the power consumption (Primary_Usage) of the primary power region in preparation for an increase in power consumption.

[0112] The controller 150 checks whether the charger 50 is in use (S324). If the charger 50 is in use, it can be controlled to proceed with charging only using grid power (S325). This is to save the power charged in the energy storage device 100 so as to assist the power consumption of the primary power region.

[0113] Also, when the charger 50 is not in use, or when the charger 50 proceeds with charging only using grid power, the controller 150 measures the SOC of the energy storage device 100 (S326). As a measurement result, if the SOC of the energy storage device 100 is below the reference value (S327), charging of the energy storage device 100 proceeds (S328).

[0114] When applying the process of FIG. 11, when the power consumption (Primary_Usage) of the primary power region increases, the energy storage device 100 can assist with power.

[0115] FIG. 12 is a diagram showing an ESS configuration according to another embodiment of the present invention. The power supplied from the outside is applied to the battery pack 110d via the ground fault device (GFD) 127d and the switch gear 125d. As a detailed configuration of the switch gear 125d, an example is a switched-mode power supply (SMPS) 121d and a pack BMS 120d. The pack BMS 120d can perform control and sensing, can control an LED and a relay, and can sense current and voltage. In FIG. 12, the switch gear 125d and the PMS 130d can constitute a controller.

[0116] FIG. 13 is a diagram showing the configuration of a charger according to an embodiment of the present invention. The charger control unit 550 controls the operation of the charger 50 and controls various components 510, 520, 530, 540 that make up the charger 50.

[0117] The interface unit 510 provides an interface so that a user can input or check information during the process of charging various devices such as an electric vehicle and an electric bicycle from the charger 50. The interface unit 510 can be composed of a touch screen and buttons.

[0118] The communication unit 520 transmits and receives information to and from an external device. The communication unit 520 can receive information such as the current available power status from the ESS 100 or the PMS 130, and information regarding whether the input power is input from the grid or the ESS. In addition, the communication unit 520 can transmit information related to the current charging progress status of the charger 50 to the ESS 100 or the PMS 130. Or the communication unit 520 can transmit information related to the current charging progress status to other chargers.

[0119] The charging unit 530 charges other devices (such as electric vehicles, electric bicycles, and electronic products). The power supply unit 540 is supplied with power from the outside and provides it to the charging unit 530. The charger control unit 550 outputs to the interface unit 510 an amount, time, option, etc. related to charging according to the source of power supplied from the power supply unit 540. The charger control unit 550 can control the charging unit 530 according to the source of power supplied from the power supply unit 540, the charging option set in the interface unit 510, etc.

[0120] The charger control unit 550 determines the charging amount or the charging time as a charging unit according to the type of the power source. The charging unit 530 proceeds with charging according to the time or amount selected by the interface unit 510.

[0121] By utilizing some or all of the features of the present invention, it can be used in a battery charging management system that can analyze the history of power usage occurring during the user's charging process at an ESS or an electric vehicle charging station, charge only for the amount of power actually charged, and analyze the power usage status and check power loss. According to an embodiment of the present invention, the battery charging management system as described above can include a means for grasping the usage or consumption details of the power delivered from the ESS and analyzing information on the energy usage and loss. Such a power usage information analysis means can solve problems caused by anomalies in the power delivered from the ESS as well as the difference between the actual power usage and the delivered power.

[0122] In order to perform various controls to supply power from the power grid to the ESS battery in the ESS operation system, various measurements, confirmations, supervision and / or monitoring of the inside of the battery, the outside of the battery, the surrounding environment and the entire system must be performed at each stage (level). According to at least one embodiment of the present invention, the monitoring levels may include four levels. Each level is connected by a network communication line and has the function of exchanging signals and issuing or executing commands with each other.

[0123] FIG. 14 is a conceptual diagram exemplarily showing the operation state management range when the monitoring level is composed of level 1 to level 4 as an example of applying part or all of the features of the present invention to the ESS security management system.

[0124] According to at least one embodiment of the present invention, the monitoring level may include level 1 including a BMS directly connected to the battery; level 2 including the above level 1 and including a master BMS to which the BMSs of level 1 are collectively connected; level 3 including the above level 2 and including a power management system (PMS) in which control is performed on one or more of heating, ventilation and air conditioning, load, and grid; and level 4 including the above level 3 and including one or more of the top-level energy management system (EMS) that controls one or more of the ESSs and power systems in various regions. When such a monitoring level is configured in four levels, specifically, a multi-level can be configured as follows.

[0125] In the battery charging management system of the ESS that utilizes such a four-level, a power usage information collection unit that collects power usage information related to the actual charging power and other power (for example, power for heaters, BMS balancing power, V2L power, external outflow loss power, etc.), an information analysis unit that classifies or analyzes the information collected by the power usage information collection unit, and a battery charging management can be executed including a charging execution unit that executes charging stop or charging state control based on such analysis results.

[0126] In addition, part or all of the features of the present invention can be utilized and applied to an electric energy supply method and its system. More specifically, it relates to an electric energy supply method for efficiently supplying power to an electric energy storage or electric energy consumption area including an energy storage device (ESS) through a grid (Grid) supplied with electricity from a power supply source, and an electric energy supply device and supply system using the same.

[0127] In addition, when supplying power from the grid and the ESS, information regarding power consumption and remaining power can be collected and evaluated to efficiently control and manage the charging and discharging of the ESS and the supply of electrical energy from the grid, etc., optimize the power amount of the grid, optimize and minimize losses due to over-power and peak power, and suppress grid overload. Also, the complementary relationship between the grid and the ESS can be maintained, and in the case of insufficient overall power supply of the grid or momentary power outages and power interruptions, high output is possible, so there is an advantage that stable supply and demand of grid power is possible.

[0128] FIG. 15 exemplarily shows a system that supplies power from the grid to the ESS and the power consumption area, controls information regarding available power obtained by the PMS of the ESS and power supply to the power consumption area, and executes electrical energy supply including ESS charge and discharge management.

[0129] An electrical energy supply system can be provided that includes an ESS that is supplied with power through the grid and performs charging and discharging, a charger that is supplied with power from one or more power sources among the ESS or the grid, and auxiliary equipment to which power of an external load of the ESS is supplied, and includes a step of storing the maximum output power that can be output by the grid; a step of measuring or receiving the power consumption amount of the external load of the ESS of the auxiliary equipment; a step of measuring the power consumption amount of the grid; and a step of controlling the charging or discharging of the ESS based on the power information collected in each of the above steps.

[0130] For example, in the case of a LIB, it generates heat and affects battery life during high power output. However, in the case of a vanadium ion battery (VIB), stable high power output is possible. Also, in the case of a LIB, there are limitations such as 1C charge and 1C discharge. However, a vanadium ion battery (VIB) can control the input / output current flow at high power. For example, when a grid power outage occurs, an ESS using a vanadium ion battery (VIB) can assist both the grid and the charger at high power. Therefore, especially in the case of an ESS applying a vanadium ion battery (VIB), the ESS charge / discharge management can be performed very efficiently. In particular, in the case of a vanadium ion battery (VIB), there is no risk of fire due to overload. When such a vanadium ion battery (VIB) is applied to the ESS of the present invention, it can be said that it is a very effective power supply system in that the electrical energy supply system of the present invention can be preferably applied while ensuring safety with various auxiliary facilities. Also, since the present invention enables safe and efficient energy supply, it can be utilized as a very effective, safe, and environmentally friendly energy supply means for energy conservation, energy environment, and carbon neutrality realization.

[0131] Additionally, it is also possible to execute High C-Rate output and cell balancing control according to the output by utilizing some or all of the features of the present invention.

[0132] FIG. 16 is a conceptual diagram showing cases of <1>, <2>, and <3> which exemplarily show various cell deviations with respect to cells of an internal battery of an ESS when the charge / discharge of the ESS is performed at a high C-rate for a specific load.

[0133] The inventors recognized the problem that the probability of cell deviation occurrence and the deviation voltage increase during high C-rate charge / discharge. As a solution, the balancing current amount can be adjusted by pulse width modulation (PWM). It can be controlled by methods such as maximum current amount balancing at high C-rate and minimum current amount balancing at low C-rate.

[0134] As a result, in order to control the balancing current in a fluid manner, it is possible to maintain a stable high C-rate. For example, when there are many cells with cell deviations, PWM control can also be executed so that more balancing is performed on specific cells.

[0135] Specific balancing methods can be applied in various ways without limitation, and it is fundamentally important to adjust the balancing current in a fluid manner. Also, after minimizing the resistance value of the balancing current limiting element to the maximum extent in a way that can protect the balancing switch element, the balancing current can be controlled by current control through PWM control.

[0136] In addition, the inventors also recognized the problem that when there are many cells that are over-discharged during high C-rate charge / discharge, there may be a concern about the suspension of cell monitoring BMS operation. In the existing configuration or prior art, when performing high-power discharge during battery power use, stable operation was impossible due to fluctuations in the input power supply of the BMS. That is, when the power supply of the BMS was cut off, the normal ESS power was usually cut off, so many difficulties occurred during high-power discharge. Also, when using an external power supply as in the existing / prior art, there were problems such as the addition of components such as a large number of connector wires, the addition of necessary manufacturing processes, and an increase in unit price due to an overall increase in cost.

[0137] As a solution, attention was paid to the fact that a boost circuit can be configured so that the BMS can operate normally as long as only the minimum voltage is input. The battery voltage can be input primarily, and the input voltage can be changed (boosted) to a voltage at which the BMS can operate and provided as the BMS power input.

[0138] As a result, the BMS can operate stably even when battery deviations occur, and the BMS can operate stably even when a large number of over-discharged batteries occur. Since only a small number of elements are added to the internal circuit board of the BMS, the increase in unit price is minimized and it can be realized without adding special processes.

[0139] Embodiments of the present invention can also be described as follows. At least some embodiments receive power from at least one of a power grid and an energy storage device (ESS), execute an electric vehicle charging procedure through a charger, receive power from at least one of the power grid and the energy storage device (ESS) and execute the charging procedure through the charger, and during the electric vehicle charging procedure, it is possible to charge the energy storage device (ESS) from the power grid or switch from discharging to charging of the energy storage device (ESS). An electric vehicle charging method is presented, characterized by this.

[0140] Here, some features of the present invention can execute the switching to charging after ESS charging or discharging while charging an electric vehicle. This is because, in order to accommodate vehicles with slow charging, ESS charging also proceeds simultaneously or together during the charging of the electric vehicle. Whether the charging speed of the electric vehicle is low speed, high speed, ultra-high speed, slow speed, rapid, etc. may be determined differently depending on the specifications, capacity, operation, commercial application, battery type, charge and discharge technology, etc. of the corresponding electric vehicle charging system. For example, currently, in some electric vehicle charging systems, slow charging takes about 10 hours or more, and rapid charging is defined as about 1 hour or so. However, the features of the present invention are fully applicable to systems with different charging speed values such as low speed, high speed, ultra-high speed, slow speed, rapid, etc., and are not limited to the exemplified charging speed names and exemplified speed values.

[0141] The electric vehicle charging procedure starts with a high-speed charging section first and then enters a low-speed charging section. In the high-speed charging section, the power grid power is mainly used to charge the electric vehicle, but the energy storage device (ESS) is discharged to assist the power grid. In the low-speed charging section, the energy storage device (ESS) is charged according to the state of the power grid.

[0142] Here, fast charging and slow charging are relative concepts to each other and may vary each time depending on the power supply status of the power grid, the discharge situation of the ESS, etc. Electric vehicle charging can basically be divided into three levels. Level 1 can be regarded as slow charging (~16A) when using a general outlet. Level 2 is charging using a 32A current, and when charging the vehicle with alternating current, it is called slow charging in Korea. Level 3 supplies direct current of 400V or more and is called rapid charging in Korea. Therefore, it can be said that in the first half of electric vehicle charging, high-speed (rapid) charging is performed with a relatively high power and fast speed direct current supply, and in the second half, low-speed (slow) charging is performed with a relatively low power and slow speed alternating current supply. As another method, whether the charging is high-speed or low-speed can also be defined and judged by the charge / discharge rate (C-rate) concept.

[0143] The state of the power grid is related to the contract power of the power grid, and the surplus output of the power grid is used for charging the energy storage device (ESS). Here, the contract power can mean the contract capacity agreed upon with the power supply company, that is, the power company. When the power company supplies electricity to consumers, it determines the supply conditions other than the electricity charge according to the electricity supply regulations. In other words, the contract power is the value obtained by converting the customer's electrical equipment into electricity, and it means the power that the electricity supply business operator (e.g., Korea Electric Power Corporation) agrees to supply to general consumers. The contract power is not only the basis for calculating the basic facility burden fee among the customer burden construction fees paid to the electricity supply business operator at the time of applying for electricity use, but also the reference value when calculating the basic charge of the electricity charge.

[0144] On the other hand, the surplus output is variable depending on the state of the power grid. As an example, the excess of the required power in the system where the ESS is installed can be regarded as the surplus. In this case, according to the present invention, control is executed so that part or all of the detected surplus output of the power grid can be used for ESS charging.

[0145] When the output of the charger drops below a reference value, the energy storage device (ESS) is charged with the power provided by the power grid. The reference value is related to the contract power of the power grid, and the surplus output of the power grid is used to charge the energy storage device (ESS).

[0146] Since the charging and discharging outputs of the energy storage device (ESS) change significantly according to the state of the power grid, a battery capable of handling the low-output to high-output range is applied to the energy storage device (ESS) to perform the discharging or charging of the energy storage device (ESS).

[0147] Here, low output and high output are relative concepts and may vary each time depending on the power supply state of the power grid, the discharging situation of the ESS, etc. Exemplarily, it can mean that in the first half of electric vehicle charging, the power is relatively high (i.e., high output) and rapid charging is performed with DC supply, and in the second half, the power is relatively low (i.e., low output) and slow charging is performed with AC supply.

[0148] An electric vehicle charging method, characterized in that during the electric vehicle charging procedure, both discharging and charging of the energy storage device (ESS) are performed. Here, the statement that both discharging and charging are performed may sometimes mean that they are performed together. However, it does not mean that the charging and discharging must be performed at the same time point. That is, it means that while the charging procedure of the electric vehicle is being executed, the ESS also discharges and charges.

[0149] During the charging process, the discharging and charging of the energy storage device (ESS) are executed over a certain period of time so as to keep the difference between the state of charge (SoC) of the energy storage device (ESS) at the start of the electric vehicle charging and the state of charge (SoC) of the energy storage device (ESS) at the end of the electric vehicle charging below a certain level.

[0150] Here, the constant level of the state of charge (SoC) can also be regarded as a condition that is satisfied if the levels at the start / end of charging are within a specific range. For example, it can be regarded that when the state of charge (SoC) at the start / end of charging is within 20% of each other, it meets the requirement of being below the constant level. The percentage (%) or specific numerical range within the corresponding range may be variable depending on the operation of the energy storage device (ESS).

[0151] In the charging process, the high-speed charging section is started first and then enters the low-speed charging section. In the high-speed charging section, the power of the power grid is mainly used to charge the electric vehicle, but the energy storage device (ESS) discharges to assist the power grid. The fixed time is the low-speed charging section.

[0152] Also, in at least some embodiments, in an electric vehicle charging system where the power grid connected to the energy storage device (ESS) has a maximum power amount, and the charger connected to the energy storage device (ESS) and the power grid has a required power amount required for electric vehicle charging, when the required power amount is greater than or equal to the maximum power amount, a first step of discharging the energy storage device (ESS) for the power in the range exceeding the maximum power amount to charge the electric vehicle; and when the required power amount is less than the maximum power amount, a second step of charging the energy storage device (ESS) with the power in the range below the maximum power amount are included, and an electric vehicle charging method is presented.

[0153] In the first step, the power of the power grid is mainly used to charge the electric vehicle as a high-speed charging section, but the energy storage device (ESS) assists the power grid. In the second step, discharging and charging of the energy storage device (ESS) are performed according to the state of the power grid as a low-speed charging section.

[0154] To determine the state of the power grid, a step of comparing the maximum power amount and the required power amount is further included. Execute the first stage and the second stage to minimize the change in the state of charge (SoC) of the energy storage device (ESS) at the start of the electric vehicle charging and the change in the state of charge (SoC) of the energy storage device (ESS) at the end of the electric vehicle charging.

[0155] Here, minimizing the change in the state of charge (SoC) can also be regarded as a condition that is satisfied if the relative change amount at the start / end of charging is within a specific range. For example, when the change in the state of charge (SoC) at the start / end of charging is within 10% of each other, it can be regarded as a state where the change is minimized. The percentage (%) or specific numerical range within the applicable range may be variable depending on the operation of the energy storage device (ESS).

[0156] Periodically sense the state of charge (SoC) of the energy storage device (ESS) and execute charging until the change is minimized for the energy storage device (ESS) at the end of the electric vehicle charging.

[0157] Since the change in the charging and discharging output of the energy storage device (ESS) is large according to the state of the power grid, apply a battery that can handle the low-output to high-output range to the energy storage device (ESS) and execute the first stage and the second stage.

[0158] The second stage further includes a third stage of executing the charging of the electric vehicle only by the power grid and determining whether to execute the charging of the energy storage device (ESS) by judging the state of the power grid during the execution of the second stage.

[0159] Additionally, in at least some embodiments, there is at least one secondary battery capable of charging and discharging; an input section that provides power from a power grid to charge the secondary battery; an output section that discharges the secondary battery to provide the corresponding power to a charger for charging an electric vehicle; and a control section operatively connected to the secondary battery, the input section, and the output section, and controlling to maintain the state of charge (SoC) of the secondary battery at the start of charging of the electric vehicle and the state of charge (SoC) of the secondary battery at the end of charging of the electric vehicle to be similar. The charging procedure is executed through the charger by receiving power from at least one of the power grid and the energy storage device (ESS), and it is characterized in that during the electric vehicle charging procedure, charging of the energy storage device (ESS) from the power grid or switching from discharging of the energy storage device (ESS) to charging is possible. An electric vehicle charging system is presented.

[0160] Here, maintaining the state of charge (SoC) to be similar can also be regarded as a condition being satisfied if the relative levels / states at the start and end of charging are within a specific range. For example, the case where the levels of the state of charge (SoC) at the start and end of charging are within 15% of each other can also be regarded as a state where they are maintained to be similar. The percentage (%) or specific numerical range within the corresponding range may be variable depending on the operation of the energy storage device (ESS).

[0161] The control section provides control for the power grid to compare the maximum power amount with the required power amount required for charging the electric vehicle by the charger connected to the power grid having the energy storage device (ESS) with the secondary battery. When the required power amount is greater than or equal to the maximum power amount, a first stage of discharging the energy storage device (ESS) for the power exceeding the maximum power amount to charge the electric vehicle is executed; and when the required power amount is less than the maximum power amount, a second stage of charging the energy storage device (ESS) with the power below the maximum power amount is executed.

[0162] In the first stage, the electric vehicle is charged mainly using the power of the power grid as a high-speed charging section, while the energy storage device (ESS) assists the power grid. In the second stage, the control unit provides control for executing all discharges and charges of the energy storage device (ESS) according to the state of the power grid as a low-speed charging section.

[0163] By including the input unit, the output unit, and the control unit, the energy storage device (ESS) can be realized with a secondary battery having a capacity smaller than that of an existing energy storage device (ESS) applying a lithium battery.

[0164] Here, having a smaller capacity compared to an existing LIB may mean that a secondary battery with a smaller required capacity can be used so that the secondary battery can exhibit similar or equivalent performance on the premise that other conditions are the same.

[0165] Since the charging and discharging outputs of the secondary battery change significantly according to the state of the power grid, a vanadium ion battery (VIB) capable of corresponding to all outputs from low output to high output is realized as the secondary battery.

[0166] Furthermore, additionally, in an electric vehicle charging system where the power grid connected to the energy storage device (ESS) has a maximum power amount, and the charger connected to the energy storage device (ESS) and the power grid has a required power amount required for electric vehicle charging, when the required power amount is less than the maximum power amount, it includes a second stage of charging the energy storage device (ESS) with power in a range below the maximum power amount, and the charging procedure is executed through the charger by receiving the power of at least one of the power grid and the energy storage device (ESS), and during the electric vehicle charging procedure, charging of the energy storage device (ESS) from the power grid or switching from discharging of the energy storage device (ESS) to charging is possible. An electric vehicle charging method is presented, characterized by this.

[0167] When the required power amount is greater than or equal to the maximum power amount, it further includes a first step of discharging the energy storage device (ESS) for the power in the range exceeding the maximum power amount to charge the electric vehicle.

[0168] Just because all the components constituting the embodiments of the invention are described as being combined or combined and operating together does not mean that the present invention is necessarily limited to such embodiments. Within the scope of the object of the present invention, all the components can also be selectively combined and operate. Also, all of its components can be realized as one independent piece of hardware, but a part or all of each component can also be selectively combined and realized as a computer program having a program module that executes part or all of the functions combined by one or a plurality of pieces of hardware. The code and code segments constituting the computer program will be easily inferred by those skilled in the technical field of the present invention. Such a computer program can be stored in a computer-readable medium and read and executed by a computer to realize the embodiments of the present invention. The storage media for the computer program include storage media including magnetic recording media, optical recording media, and semiconductor recording elements. Also, the computer program for realizing the embodiments of the present invention includes a program module transmitted in real time through an external device.

[0169] The above-described embodiments should be understood as being illustrative in all respects and not restrictive, and the scope of the present invention will be shown by the claims described later rather than the above-described detailed description. And of course, all conversions and deformable forms derived from the equivalent concept of the meaning and scope of this claim should be interpreted as being included in the scope of the present invention.

Claims

1. The system receives power from at least one of the power grid and / or energy storage devices (ESS), and performs the electric vehicle charging procedure through a charger. An electric vehicle charging method characterized in that it receives power from at least one of the power grid and the energy storage device (ESS) and executes the charging procedure through the charger, and during the electric vehicle charging procedure, it is possible to switch from charging the energy storage device (ESS) from the power grid or from discharging the energy storage device (ESS) to charging.

2. The electric vehicle charging method according to claim 1, characterized in that the electric vehicle charging procedure starts a fast charging section first and then enters a slow charging section, in the fast charging section the electric vehicle is charged mainly using the power of the power grid but the energy storage device (ESS) is discharged to assist the power grid, and in the slow charging section the energy storage device (ESS) is charged according to the state of the power grid.

3. The electric vehicle charging method according to claim 2, characterized in that the state of the power grid is related to the contracted power of the power grid, and the surplus output of the power grid is used to charge the energy storage device (ESS).

4. In the electric vehicle charging method according to claim 1, when the output of the charger falls below a reference value, the energy storage device (ESS) is charged with power provided from the power grid. The electric vehicle charging method is characterized in that the aforementioned reference value is related to the contracted power of the power grid, and the surplus output of the power grid is used to charge the energy storage device (ESS).

5. An electric vehicle charging method according to claim 1, characterized in that, because the charging and discharging output of the energy storage device (ESS) changes significantly depending on the state of the power grid, a vanadium-ion battery (VIB) capable of handling a range from low to high output is applied to the energy storage device (ESS) to perform discharging or charging of the energy storage device (ESS).

6. An electric vehicle charging method according to claim 1, characterized in that the discharge and charging of the energy storage device (ESS) are all performed during the electric vehicle charging procedure.

7. An electric vehicle charging method according to claim 1, characterized in that, during the charging process, the discharge and charging of the energy storage device (ESS) are performed over a certain period of time such that the difference between the charge state (SoC) of the energy storage device (ESS) at the start of electric vehicle charging and the charge state (SoC) of the energy storage device (ESS) at the end of electric vehicle charging is kept below a certain level.

8. The electric vehicle charging method according to claim 7, characterized in that the charging process starts with a fast charging section and then enters a slow charging section, in the fast charging section the electric vehicle is charged mainly using the power of the power grid, but the energy storage device (ESS) is discharged to supplement the power grid, and the slow charging section is used for a certain period of time.

9. In an electric vehicle charging system in which a power grid connected to an energy storage device (ESS) has the maximum amount of power, and a charger connected to the energy storage device (ESS) and the power grid has the required amount of power required for electric vehicle charging, If the requested power amount is equal to or greater than the maximum power amount, the first step is to charge the electric vehicle by discharging the energy storage device (ESS) with respect to the power exceeding the maximum power amount; and An electric vehicle charging method characterized by including a second step of charging the energy storage device (ESS) with power in a range below the maximum power amount when the requested power amount is less than the maximum power amount.

10. The electric vehicle charging method according to claim 9, characterized in that the first stage is a fast charging section in which the electric vehicle is charged mainly using the power of the power grid, but the energy storage device (ESS) assists the power grid, and the second stage is a slow charging section in which the discharge and charging of the energy storage device (ESS) are performed according to the state of the power grid.

11. An electric vehicle charging method according to claim 10, further comprising the step of comparing the maximum power amount with the requested power amount in order to determine the state of the power grid.

12. An electric vehicle charging method according to claim 9, characterized in that the first and second steps are performed to minimize the change in the charge state (SoC) of the energy storage device (ESS) at the start of electric vehicle charging and the change in the charge state (SoC) of the energy storage device (ESS) at the end of electric vehicle charging.

13. An electric vehicle charging method according to claim 12, characterized in that the charge state (SoC) of the energy storage device (ESS) is periodically sensed and charging is performed to the energy storage device (ESS) at the end of electric vehicle charging to a level that minimizes the change.

14. An electric vehicle charging method according to claim 9, characterized in that, because the charging and discharging output of the energy storage device (ESS) changes significantly depending on the state of the power grid, a vanadium-ion battery (VIB) capable of handling a range from low to high output is applied to the energy storage device (ESS) and the first and second steps are performed.

15. The electric vehicle charging method according to claim 9, further comprising a third step in which the second step is to charge the electric vehicle using only the power grid, and the state of the power grid is determined during the execution of the second step to decide whether to charge the energy storage device (ESS).

16. At least one rechargeable and dischargeable secondary battery; An input unit that receives power from the power grid to charge the aforementioned secondary battery; An output unit that discharges the secondary battery and provides the corresponding power to a charger for charging an electric vehicle; and The system includes a control unit that is operationally connected to the secondary battery, the input unit, and the output unit, and controls the system to maintain a similar state of charge (SoC) of the secondary battery at the start of electric vehicle charging and the state of charge (SoC) of the secondary battery at the end of electric vehicle charging. An electric vehicle charging system characterized by receiving power from at least one of the power grid and an energy storage device (ESS) and performing a charging procedure through the charger, and being able to switch from charging the energy storage device (ESS) from the power grid or discharging the energy storage device (ESS) to charging during the electric vehicle charging procedure.

17. In the electric vehicle charging method according to claim 16, The power grid compares the maximum amount of energy and the energy storage device (ESS) equipped with the secondary battery with the charger connected to the power grid, and the amount of energy required for charging an electric vehicle. If the requested power amount is equal to or greater than the maximum power amount, the first step is to charge the electric vehicle by discharging the energy storage device (ESS) with respect to the power exceeding the maximum power amount; and An electric vehicle charging system characterized in that, if the requested power amount is less than the maximum power amount, the control unit provides control for performing a second stage of charging the energy storage device (ESS) with power in a range below the maximum power amount.

18. An electric vehicle charging system according to claim 17, characterized in that the first stage is a fast charging section in which the electric vehicle is charged mainly using the power of the power grid, but the energy storage device (ESS) assists the power grid, and the second stage is a slow charging section in which the control unit provides control to perform all discharge and charging of the energy storage device (ESS) according to the state of the power grid.

19. An electric vehicle charging system according to claim 16, characterized in that by comprising the input unit, the output unit, and the control unit, the energy storage device (ESS) can be realized with a secondary battery having an even smaller capacity than that of an existing lithium battery-based energy storage device (ESS).

20. An electric vehicle charging system according to claim 16, characterized in that, because the charging and discharging output of the secondary battery changes significantly depending on the state of the power grid, a vanadium-ion battery (VIB) capable of handling all output levels from low to high is used as the secondary battery.

21. In an electric vehicle charging system in which a power grid connected to an energy storage device (ESS) has the maximum amount of power, and a charger connected to the energy storage device (ESS) and the power grid has the required amount of power required for electric vehicle charging, If the requested power is less than the maximum power, the second step includes charging the energy storage device (ESS) with power within a range below the maximum power. An electric vehicle charging method characterized in that it receives power from at least one of the power grid and the energy storage device (ESS) and performs a charging procedure through the charger, and during the electric vehicle charging procedure, it is possible to switch from charging the energy storage device (ESS) from the power grid or from discharging the energy storage device (ESS) to charging.

22. The electric vehicle charging method according to claim 21, further comprising a first step of discharging the energy storage device (ESS) with respect to power exceeding the maximum power amount when the requested power amount is equal to or greater than the maximum power amount, thereby charging the electric vehicle.

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